For fixed installations choose the plug pack. For other applications use a 9V battery (

Unlike line level audio sources you connect to a stereo (DVD/CD players, tape decks, TV audio, minidisc, etc.), the output from a magnetic cartridge installed in a good qualityturntable is MUCH lower, and requires an additional stage ofamplification to bring it up to the same volume as the othersources you listen to through your stereo. This additional amp stage, the phono preamp, is built-in to most older receivers and amps, allowing direct connection of a turntable. However, newer stereo equipment (including virtually all mini-systems and home theatre units, as well as many stereo receivers and amps), do not have a phono input (this is because records and turntables are supposedlyobsolete in today’s world dominated by CDs and DVDs). In order to utilise the inputs that such units have (Aux, Tape, Line, Video, CD, etc.) to connect a turntable, you need to first pass the signal thru an external phono preamp to bump the level. The same level increase is needed if you’re connecting a turntable to a computer sound card’s line input so you can make CD-Rs from LPs; again, the external phono preamp provides it